Study on the Influence of Sponge Road Bioretention Facility on the Stability of Subgrade Slope

With the large-scale application of sponge city facilities, the bioretention facility in urban roads will be one of the key factors affecting the safety of construction facilities in areas with abundant rainfall. In this study, by establishing a three-dimensional finite element model for numerical analysis and combining it with geotechnical tests, the effects of bioretention facility on water pressure distribution, seepage path, and slope stability under rainwater seepage conditions are proposed. In addition, this study puts forward the relationship between the parameters of the bioretention facility and the stability of the slope in combination with the effect of runoff pollution control, which provides direction and basis for the planning, design, and construction of sponge cities in road construction.

Simulation of Urban Storm Water Runoff Control Based on Big Data

The acceleration of urbanization has brought about rapid economic development, but at the same time, it has also brought some damage to the ecological environment. The proportion of hardened area of the ground is higher and higher, and the rainwater runoff pollution caused by rainfall is more and more serious. In order to follow the sustainable development strategy, and for the more stable and high-speed economic development, the control of rainwater runoff pollution is urgent. The purpose of this paper is to simulate the urban storm water runoff control and find the most suitable scheme for storm water runoff pollution control. Because the simulation of SWMM is more accurate than other models, it can directly reflect the situation of rainwater runoff pollution, so the model selected for rainwater runoff in this paper is SWMM, and then build the model, through the collection and collation of the basic data of the study area, the generalization of the sub catchment area and drainage network is completed. Through the analysis of the characteristics of the study area, the rainwater garden and permeable pavement are determined as the scheme to control the rainwater runoff in the study area. Finally, the SWMM model is used to simulate the control effect of rainwater garden and pervious pavement on rainwater runoff pollution control. The experimental results show that the storm water garden can effectively control the impact of SS scouring effect on the environment, significantly reduce the discharge of SS, and significantly reduce the peak concentration of SS, and its ability to control SS increases with the thickness of the surface plant layer. The control ability of rain permeable brick pavement to SS increases with the increase of surface porosity, that is, the control effect of SS is the best when the porosity is 20%.

Pollutant first flush identification and its implications for urban runoff pollution control: a roof and road runoff case study in Beijing, China

First flush is a common phenomenon in urban runoff pollution. Typical cement roof and asphalt road runoff in Beijing, China were monitored for 2 years. Based on the M(v) curve, the suspended solids (SS), chemical oxygen demand (COD), total phosphorus (TP) and particulate phosphorus in cement roof runoff presented a stronger first flush than those in asphalt road runoff. The first flush volume (VFF) of SS, COD, total nitrogen (TN) and TP in asphalt road runoff differed slightly from the cement roof. There were also differences in the first flush assessment depending on which method was used. We proposed a new method based on the runoff depth versus pollutant cumulative mass curve. According to the national standards in China (VFF = 3 mm), various masses of different pollutants, such as 91.42 ± 9.80% (cement roof) and 78.49 ± 19.41% (asphalt road) of SS and 86.85 ± 13.54% (cement roof) and 72.80 ± 25.79% (asphalt road) of COD, can be effectively controlled, but our mass control efficiencies were 55.91%–66.65% when VFF = 1 mm. The new method proposed in this study provides an alternative approach for assessing runoff pollution control efficiency of different VFF.

Runoff pollution control of a sewage discharge project based on green concept – a sewage runoff pollution control system

The problem of runoff pollution in sewage discharge projects mainly depends on manual inspections, and this traditional inspection method has high personnel and time costs. Moreover, with rapid development of the Internet of Things technology, application of intelligent information management has become a development trend of various neighborhoods where LoRa communication technology with low power consumption and long-distance transmission characteristics has been widely used. Therefore, starting from the concept of green environmental protection, LoRa technology is used in this paper to design and develop a runoff pollution control system including a management terminal, terminal and network components for waste-water discharge projects. The main function is to calculate and comprehensively analyze the conventional indexes such as CODCr, BOD5, ammonia nitrogen, and total phosphorus in the sewage treatment process, which reduces the calculation error of total pollutant treatment volume and total production volume, and improves the data accuracy of the sewage purification project. Meanwhile, the example verifies that the system proposed in the paper has accurate analysis of runoff pollution characteristics and accurate data calculation, which provides technical support for sustainable development and green development goals and mitigation of water crisis.

Study on purification effect of infiltration materials to pavement runoff pollution

The concentrations of pollutants in pavement runoff are higher than those in other surface runoff normally, which causes serious problems in protecting the environment of receiving rivers and soils. According to the concept of low impact development (LID), a pavement runoff pollution control measure was developed by using infiltration structure. In order to infiltration structure play a superior role in the control of pavement runoff pollution, purification capacity of four typical infiltration materials was tested. Then, long-term purification efficiency of infiltration materials was explored to suspended solids. Besides, microscopic observation was performed on infiltration materials. Results indicated that purification effects of infiltration materials were significantly different. The purification process can be divided into three stages, which ware "rapid upgrading ", "slow upgrading " and "slow reduction ". Finally, Infiltration materials mainly have two modes to intercept runoff pollutants, which were pore adsorption and mechanical interception of the gap between materials.

Discussion about initial runoff and volume capture ratio of annual rainfall

In recent years, runoff pollution from urban areas has become a major concern all over the world. But there exists a worldwide confusion about how much stormwater should be captured for the purpose of runoff pollution control. Furthermore, the construction cost and pollution control efficiency are closely linked with the size of stormwater facilities, which is then related to the first flush (FF) phenomenon and volume capture ratio of annual rainfall (VCRa). Based on this background, analysis of the random and changeable characteristics of the occurrence of FF was carried out first, which was proved to vary with catchment characteristics and pollutant types. Secondly, the distribution of design rainfall depth toward 85% VCRa in China and its causes have been analyzed. Thirdly, the relationship between initial runoff and VCRa has been studied at both conceptual and numerical levels, and the change rule of VCRa along with design rainfall depth in different regions has been studied. The limitation of initial runoff has been illustrated from the perspective of runoff characteristics of single rainfall events in the first part, and from the perspective of regional differences in the two subsequent parts.